Co-Op Now

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds significant behavior beyond the annotations: unknown metadata is treated as unknown rather than 'no', party size is canonical co-op group data never server capacity, and results carry source/URL attribution obligations. These are important behavioral traits not visible in the schema or annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three dense sentences, each earning its place. The purpose is front-loaded, core caveats are stated, and the attribution requirement is included without padding.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 7-parameter read-only tool with an output schema, the description covers all necessary behavioral cautions, source identification, and link-handling expectations. Nothing critical is missing for correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description adds useful semantic context beyond the schema: canonical party size semantics, unknown-never-'no' behavior, and the distinction between platform availability and crossplay. It does not deeply describe every parameter but meaningfully augments the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'Find published co-op games from Co-Op Now' matching concrete co-op intent. It distinguishes this tool from siblings by naming the source and the unique filtering dimensions (party size, play style, platform, crossplay, session length).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives clear context for when to use this tool: when the agent needs games matching exact co-op criteria from Co-Op Now. It does not explicitly name alternatives or exclusion conditions, such as 'use search_games for general queries', so it stops short of full guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description goes beyond the readOnlyHint and idempotentHint annotations by disclosing that results are public, that capacity fields are reported distinctly, and that the response carries source, canonical_url, and a UTM-tagged open_url. It also adds the important behavioral instruction to attribute Co-Op Now and include the link when the client supports citations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, each earning its place: the first explains the operation, the second details key result fields, and the third gives citation behavior. The most important information is front-loaded, and there is no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a one-parameter read-only fetch with an output schema present, the description covers the tool's role, how to obtain the id, what notable fields to expect, and how to handle attribution. Nothing essential is missing for an agent to invoke it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema already documents the single id parameter with the same source guidance as the description ('Game id from search_games or find_coop_games'). Since schema_description_coverage is 100%, the description adds no new meaning beyond restating the param origin, so baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'Fetch full public details for one Co-Op Now catalog game by id'. It clearly distinguishes this as a detail-retrieval tool versus the search/list siblings by requiring an id from search_games or find_coop_games.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description clearly implies the intended flow: get an id via search_games or find_coop_games, then call get_game for full details. It does not explicitly state when not to use it, but the context is clear enough for an agent to route correctly.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already cover read-only and idempotent behavior, so the description goes further by disclosing important output and citation behavior: canonical_url vs. UTM-tagged open_url, the required source attribution, and response-level attribution for picks without a game id. This adds meaningful operational context beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The core purpose is front-loaded and the description avoids fluff, but the first sentence is dense and packs several clauses about links, source, and client support into one long statement. Still, every clause adds relevant information, so it is more structured than bloated.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

This is a simple one-parameter read-only list tool with an output schema, so the description adequately covers the important non-obvious aspects: source attribution and link behavior. The annotations handle safety, and the schema handles parameter and return details, leaving no critical gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The only parameter, limit, is fully documented in the schema with default, min, and max values, so the description carries little parameter burden. The description adds no extra parameter-specific meaning beyond already-schema-covered details, so the high-coverage baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific action ('Return community-picked underrated co-op games') and a clear resource ('Co-Op Now's Hidden Gems list'). It clearly differs from the sibling search tools by emphasizing hidden/curated picks, though it does not explicitly name which sibling it is not.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The use case is implied: this is the tool for curated, underrated co-op recommendations rather than broad search or lookup. However, it never explicitly explains when to prefer this over find_coop_games or search_games, nor does it give any exclusion guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and idempotentHint=true, lowering the bar. The description adds useful behavioral context: it returns a canonical party size distinct from server/session capacity, includes a UTM-tagged open_url, identifies Co-Op Now as source, and instructs the agent to cite the link when the client supports citations. No contradictions with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core action and resource, then efficiently packs return fields, citation guidance, and routing to a sibling. Each sentence earns its place; there is no filler or repetition of schema details.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With annotations covering safety (read-only, idempotent), a 100%-documented schema, and an output schema present, the description is complete for correct invocation. It explains the return fields plus how to handle source and links, and routes to the right sibling tool. Nothing essential is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description reiterates that 'query' matches against title but adds no format, syntax, or interpretation details beyond the schema. The limit parameter is already fully documented in the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Look up') and resource ('games by title in Co-Op Now's public co-op catalog'), clearly distinguishing it from find_coop_games, which is explicitly named as the structured-discovery alternative. An agent can immediately understand what this tool does and how it differs from its siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly states when to use this tool (title lookup) and names the alternative for structured discovery: 'Use find_coop_games for structured discovery by party size, play mode, platform or session length.' This gives clear routing guidance with a specific condition.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.