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

No annotations contradict description: readOnlyHint=true aligns with 'fetches'. Description adds behavioral context: locale changes language, not editorial scope, and lists included sections (headline, charts, etc.), all beyond 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 short sentences, each earning its place: purpose, usage guidelines, and locale clarification. No wasted words.

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?

Tool has low complexity (1 optional param, output schema present). Description covers purpose, usage constraints, and behavioral nuance. Output schema handles return values, so no further detail needed.

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?

Only one parameter, locale, with enum in schema but no description. Description adds value: 'Locale changes the brief's language, not its editorial scope.' Schema coverage is 0%, but description compensates with clear semantic guidance.

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 fetches Pollar's daily brief with specific components (greeting, headline, executive summary, themed sections, events, charts). It distinguishes from sibling tools by emphasizing it's a curated digest, not a general search.

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?

Explicitly tells when to use: 'only when the user explicitly asks for Pollar's daily brief or curated digest.' Also tells when not to use and provides an alternative: 'Do not use it for questions about a subject... use search_news instead.'

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