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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), and the description adds two facts not derivable from them: no invitation/notification is dispatched, and duplicates are possible so a prior list is required. It does not say what happens when a duplicate is submitted (error vs. created) or what permissions are needed.

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 short sentences, zero filler, with the action front-loaded and the prerequisite/side-effect notes immediately after. Every sentence carries distinct information.

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 5-parameter, 1-required tool with annotations present, the description covers purpose, a dedupe prerequisite, and the key side effect. No output schema exists and the description does not indicate what is returned (e.g., the created signer id needed by downstream tools), which is the main 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 only 60%, and the description adds no parameter meaning at all — it never mentions full_name, email, or the optional account_id/government_id/whatsapp fields. The schema does document the non-obvious fields (normalization, CPF/CNPJ requirement, OAuth-derived account_id), so the baseline 3 applies rather than a penalty.

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?

States a specific verb and resource ('Create a signer') plus its scope ('in the workspace'), which cleanly separates it from the sibling read/update tools (assinafy_get_signer, assinafy_list_signers, assinafy_update_signer). An agent can identify the operation without opening the 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?

Gives an explicit prerequisite and alternative: 'Search with assinafy_list_signers first to avoid duplicates.' It also clarifies the tool's relationship to the notification flow ('Sends no invitation'), implying the agent must separately trigger sending. It stops short of naming update_signer as the path for existing signers, so it is clear but not complete on when-not-to-use.

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