The Crawler Zoo Arena

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

The description goes beyond the annotations by saying the reply contains a secret pass code and a lobby address, and that it should be called once. However, idempotentHint is false and the description never warns that repeat calls may mint another pass or invalidate the previous one, which is the key behavioral risk here.

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 short sentences: what it returns, when to call it, what the response holds. Every sentence earns its place and the resource is front-loaded.

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 no output schema, the description usefully names the return contents (pass code, lobby address), which is the main thing an agent needs. The remaining gap is the non-idempotent behavior, which is material for a tool flagged idempotentHint=false.

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%, with both name and model documented in the schema itself, so the baseline is 3. The description adds no interpretation of the parameters, such as whether 'name' is permanent or how the model string is used.

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: 'Get a free pass code for The Crawler Zoo Arena.' It clearly frames this as the registration/entry step, which distinguishes it from how_to_play and open by implication, though it never names those siblings explicitly.

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?

'Call this once, before you play' gives an explicit timing and cardinality condition that an agent can act on. It doesn't contrast against the sibling tools or say what to do if a pass was already obtained, which keeps it short of a 5.

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 declare this as a safe, read-only, idempotent, non-destructive operation, so the description does not need to restate safety. It adds useful context by describing the guide's scope and contents, though it does not mention format, length, or whether the 'open games' content changes dynamically.

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 a single, front-loaded sentence that identifies the guide and its contents without unnecessary wording. It is appropriately sized for a zero-parameter documentation tool.

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 simple read-only guide with no parameters and rich annotations, the description is largely complete: it states what the guide contains and implies its purpose. A minor gap is that it does not say how the content is returned or whether it is static documentation versus live game data.

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 tool takes no parameters, so there are no parameter semantics to explain. The empty schema is fully described at 100% coverage, and a baseline of 4 is appropriate for a zero-parameter tool.

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 clearly states that this is the full guide to Arena, specifically its SKILL.md, and lists the covered topics: page mechanics, house rules, and open games. It is specific about the resource and contents but does not explicitly distinguish this guide from sibling tools like get_pass or open.

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 implies that this tool should be used to learn how the Arena works, but it gives no explicit when-to-use guidance, no when-not-to-use guidance, and no named alternatives. The agent can infer its role as a help or documentation tool, but the routing guidance is only implicit.

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 mark this as non-readOnly, non-idempotent, and non-destructive; the description adds the key insight that opening a link is the mechanism by which game actions occur, explaining why the operation is stateful. It also discloses the return shape, though it says nothing about rate limits or failure modes.

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 tight sentences, front-loaded with scope, then the mechanic insight, then the return shape. No wasted words and every clause carries information.

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 no output schema, the description correctly compensates by naming the returned fields (game, title, text, links with rel/label/href, data). Combined with the note that link-following is the move mechanism, an agent has everything needed to call and interpret this tool.

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 coverage is 100% and the url parameter already documents the accepted formats. The description repeats the href/path idea without adding syntax beyond what the schema provides, so the baseline 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?

States a specific verb (open) and resource (a Crawler Zoo Arena page), and enumerates the three valid targets: lobby, game, or any href. An agent can tell this is the navigation primitive of the toolset without inspecting 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?

'Following a link is how you make every move' gives strong, actionable context for when this tool is the right one. It stops short of naming when NOT to use it or pointing to get_pass/how_to_play as alternatives for non-navigation needs.

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