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

Annotations already declare readOnlyHint/idempotentHint true and destructiveHint false, and the description adds real behavior beyond them: unresolved placeholders are left verbatim and surfaced in unresolved_variables, which must be reviewed before sending. It does not describe pagination or limits, but the response-content caveat is valuable given there is no output schema.

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?

It is front-loaded with what is returned, then the unresolved-variable caveat, then the send follow-up, then the read-only note. Dense and mostly waste-free, though 'Lecture seule' partially duplicates the readOnlyHint annotation.

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 schema-less read tool with full safety annotations, it covers the essentials: what is rendered, what happens to unresolved variables, and which tool performs the send. What is missing is minor (no note on how the resolved text is formatted or any size limits).

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% with only two UUID parameters (template_id, lead_id) already documented in the schema. The description only implicitly confirms the contact/template pairing and 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 names a specific verb (renvoie/rend) and resource (le texte d'un modèle rempli pour un contact) and even lists the interpolated variable syntax ({prénom}, {ig_handle}, {date}, {stage_pipeline}), making it clearly distinct from ficiel_list_templates, ficiel_save_template and ficiel_send_message.

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?

It routes the agent explicitly: 'N'envoie rien : le texte obtenu s'envoie ensuite avec ficiel_send_message (destinataire nommé obligatoire)', which names the sibling to use for the actual send and implies the review-before-send workflow. It does not give an explicit 'do not use this when…' clause, so it stops short of a 5.

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