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

Annotations cover only the safety profile (readOnlyHint=false, idempotentHint=false, openWorldHint=true), while the description adds substantive behavior: a per-channel rate limit with a 60 s wait, and a precise error taxonomy (send_failed, not_connected with the missing connectUrl, provider_error) explaining what each failure means and who caused it. This is exactly the kind of context annotations cannot carry.

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?

A short, front-loaded paragraph: purpose first, then rate limit, then error semantics. Every sentence carries information, though the error clause is dense enough that a slightly more scannable structure would help.

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?

There is no output schema, so the description carries the return-side burden and does so: success is implied by sending the test, and every failure mode is enumerated with its cause. For a single-parameter tool this is complete enough to invoke and interpret correctly.

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, and schema description coverage is 100% — the schema already explains 'id do canal (campo `id` de listar_canais)'. The description's 'por canal' phrasing reinforces the per-channel scoping but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 verb and resource: sending the panel's test message through the channel. This is clearly distinct from sibling operations like criar_canal, vincular_canal, or remover_canal, so an agent can pick it out without opening a schema.

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 rate limit ('1 teste por minuto por canal') and the error taxonomy give strong operational context, but the description never states when to reach for this tool versus alternatives (e.g., after criar_canal/vincular_canal) or when not to use it. Usage is implied rather than stated.

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