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

Annotations already indicate readOnly, idempotent, non-destructive. Description adds valuable detail: reads a specific internal file (filing.parquet) and has a concurrency limit, which helps the agent understand performance and constraints.

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 concise sentences with front-loaded purpose. No wasted words. Includes purpose, alternative tools, and a key constraint efficiently.

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?

Given output schema exists (explains return values), the description covers: what it does, what data it accesses, when to use alternatives, and a usage limit. Complete for a diff/list 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 descriptions cover all parameters (100% coverage), so description adds little beyond clarifying 'since' as a cutoff date. Description's concurrency note is about usage, not parameter meaning. Baseline score of 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?

Clearly states 'Return new SEC filings across the caller's watchlist tickers since a given date.' Differentiates from sibling tools by explicitly noting it does not use insider/ratio surfaces, and instructs to use those separately.

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?

Provides context on data source (filing.parquet) and concurrency bounding (max 50 tickers). Advises when not to use by pointing to other tools. Could be more explicit about exact circumstances, but sufficient.

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