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

Annotations already declare write/destructive/non-idempotent/open-world, so the description's real contribution is the AgendaPro validation rule (first_name plus at least one of last_name, email or phone) and the side-effect disclosure that no message is sent to the client. 'Not idempotent' restates the annotation, but the duplicate-creation and no-notification context adds genuine value for a mutation tool.

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?

Everything is packed into two short sentences with no filler: write intent, validation rule, dedupe guidance, side effect, endpoint. The most decision-critical facts (WRITE, search first) are front-loaded.

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 15-parameter mutation with no output schema, the definition covers the write semantics, the required-field rule, duplicate risk and the absence of client notification. It leaves unclear what is returned on success and what happens if a duplicate is submitted anyway, but nothing essential to calling it correctly is missing.

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%, so the 15 field descriptions already carry their own meaning (baseline 3). The description still adds a constraint the schema does not encode — the schema requires only first_name, yet the tool rejects calls without one of last_name/email/phone — which is exactly the kind of cross-parameter rule an agent would otherwise get wrong.

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?

Opens with an explicit 'WRITE: create a new client' verb+resource+operation-type framing, which immediately separates it from agendapro_get_client, agendapro_list_clients and agendapro_update_client. The API endpoint (POST /v3/clients) confirms the resource unambiguously.

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 the agent to call agendapro_search_clients first to avoid duplicates, and states the tool is not idempotent. It does not, however, name agendapro_update_client as the route for existing clients, so the boundary with the update sibling is left implicit.

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