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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds genuinely useful behavioral context that the annotations do not: the advice is free and 'he does not sell cars', which shapes how the agent should frame the answer and prevents it from misrepresenting the contact as a sales channel. What it does not disclose is the shape of the returned contact options or whether the channel param filters the result set.

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?

Two short sentences, front-loaded with the resource and channels, and the closing 'He does not sell cars' earns its place as a disambiguation cue. No filler or repetition of the title.

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 simple one-optional-param read tool with full annotation coverage and no output schema, the description supplies enough for an agent to invoke it correctly and to frame the response. A brief note on what the return value contains (per-channel handles only, or all channels when unfiltered) would close the remaining gap.

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% and the single optional 'channel' parameter has an enum of email/whatsapp/form, so the schema already does the work. The description restates the same three channels but adds no semantics about filtering behavior — e.g. whether omitting channel returns all channels or a default one — so it sits at the baseline.

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 names the concrete resource — a person's contact channels (WhatsApp, email, form) for free used-car advice — which is specific enough to distinguish it from the sibling tools (get_model, list_guides, etc.), which all deal with car data rather than contact routes. It only lacks an explicit verb form, but the resource is unambiguous.

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?

Usage is only implied: an agent can infer it should call this when a user wants to reach Anthony Hunt, and the phrase 'free used-car advice' gives the qualifying context. There is no explicit when/when-not guidance and no mention of the sibling tools or what to do if a channel is unavailable.

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