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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, covering the safety profile. The description adds useful behavior details: returns up to `limit` AtomEntry objects and advises using the `link` field for navigation. This clarifies result structure without contradicting 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 description is compact and well-structured: it opens with the primary purpose, immediately gives usage guidance, then provides example expressions. Every sentence adds value with no redundant fluff, making it easy to scan.

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 search tool with a query expression language, the description covers purpose, usage, parameter semantics, and navigation next steps. The output schema handles return value details, and the included examples provide essential syntax that would otherwise require external documentation.

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?

With 0% schema description coverage, the description fully compensates by explaining the limit parameter ('Returns up to `limit` AtomEntry objects') and illustrating the search_expression syntax through multiple examples. Both parameters are effectively documented beyond the raw 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 states it searches WhatDoTheyKnow's feed-based event index to find FOI requests matching a query expression, distinguishing it from sibling tools like search_authorities. It even provides example query expressions, making the tool's purpose unmistakably specific.

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 says 'Call this to find FOI requests matching a query expression' and gives guidance on next steps (extract slug, call get_request_detail or get_request_feed_items for full detail). While it doesn't explicitly contrast with search_authorities, the clear usage context and example expressions provide strong guidance for when to use this tool.

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