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

Annotations already cover readOnlyHint/idempotent/destructive=false, and the description reinforces 'Lecture seule.' It adds real behavioral context beyond annotations: the returned fields, the legacy=true flag with its consequence (tags/notes cannot be restored), and the linkage of merge_id to the unmerge tool. It does not describe pagination or filtering behavior, keeping it from a 5.

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?

Single dense sentence front-loads the core scope ('fusions ENCORE ACTIVES... fiche principale') then lists fields and the legacy caveat. All content earns its place, though the enumeration of returned fields and mid-sentence reference to another tool slightly compress readability.

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 read-only, single-parameter list tool with no output schema, the description supplies the essential missing pieces: what is returned, the meaning of merge_id, the legacy caveat, and the read-only stance. Adequate for correct invocation; only filtering/pagination and empty-result behavior are unaddressed.

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 (lead_id) with 100% schema coverage that already documents it as the primary contact. The description adds no syntax, format, or edge-case detail for lead_id beyond implying it is the subject fiche. Baseline 3 holds when the schema does the heavy lifting.

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 (Liste) and resource (fusions ENCORE ACTIVES) scoped to the primary fiche, and explicitly names the returned fields (merge_id, fiche réunie, date, auteur, conversations déplacées). It also cross-references the sibling ficiel_unmerge_leads, making it clearly distinguishable from ficiel_merge_leads.

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?

Implicitly clarifies the use case: return only active merges where this contact is the main fiche. It explicitly points to ficiel_unmerge_leads for the merge_id's purpose, but does not state when NOT to use it (e.g., use ficiel_get_lead for general contact info) nor name a direct alternative for listing passive/legacy merges.

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