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

Annotations already declare readOnly, idempotent, non-destructive, openWorld. The description adds the crucial behavioral fact 'Nothing is sent or stored,' which directly corroborates the read-only annotation and tells the agent this is purely generative. It doesn't cover rate limits or auth, but for a local text-generation tool the key disclosure is present.

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, front-loaded with the artifact, then the trigger, then the output shape and the no-side-effect guarantee. Efficient, though the example phrase is embedded in the body rather than separated, adding mild density.

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 an 8-param, no-output-schema tool, the description covers purpose, output format, and the no-store guarantee. One gap: it doesn't explain how the 'why_fit' and 'how_you_know' inputs shape the generated note, but the schema descriptions and readOnly annotations fill most of the remaining need.

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%, so the schema already documents all 8 parameters, including the 'referral (default) or chat' enum-like hint. The description adds no parameter-level detail beyond what the schema provides, which matches the baseline 3 for high coverage.

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 artifact (a ready referral note), the exact example trigger, and the two concrete outputs (a <300-char LinkedIn note and a longer email). No sibling tool produces this artifact, so the agent can distinguish it from networking_plan or find_people without opening schemas.

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 'For "write to Amy at Monzo asking for a referral"' phrase gives a clear trigger context, and the description implies the ask/chat distinction. It does not explicitly name sibling alternatives (e.g. networking_plan) or say when not to use this tool, so it falls short of full routing guidance.

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