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

Annotations already establish readOnlyHint=true and openWorldHint=false. The description adds useful behavioral context: stories are editorially clustered summaries, always carry source name and URL, results are newest-first, and at least one filter is required. No contradiction 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?

Three sentences pack the core purpose, data characteristics, ordering behavior, filter requirement, and a routing hint with no fillter. The most decision-relevant information 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?

For a read-only search tool with well-documented parameters and no output schema, the description covers the key facts an agent needs: what is searched, what a story contains, the filter requirement, ordering, and how to discover tags/date ranges. It does not enumerate all returned fields, but enough is conveyed.

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%, so the schema carries most parameter meaning. The description adds the cross-parameter rule that at least one filter must be supplied, which is valuable, but it does not add individual parameter details beyond 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 clearly identifies a specific action and resource: searching carbon.fyi's curated voluntary carbon market story archive. It explains what a story is, but it does not explicitly distinguish this search tool from sibling get_story or list_sources, so it is clear without direct sibling differentiation.

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 explicit usage context: supply at least one filter, expect newest-first results, and call get_market_summary first if tags or date range are unknown. It names an alternative for discovery but does not fully spell out when not to use this tool versus every sibling.

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