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

Annotations already declare non-readOnly, idempotent, destructive, open-world. The description adds genuine context beyond them: the gallery address/slug is unchanged and photos, logo and welcome text are untouched, clarifying the mutation is a partial field update. Permissions/auth requirements are not discussed, keeping it short of 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?

Three short sentences, front-loaded with the action and fields, followed by exclusions and a lookup hint. No filler and every sentence carries actionable 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 partial-update mutation tool with no output schema, the description covers scope boundaries, the slug prerequisite and the non-changing address. Minor gaps remain (return value, permission/ownership requirements) but nothing essential for correct invocation 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 description coverage is 100% and the schema itself carries rich enum semantics (font meanings, theme hex colors, slug pattern). The description only names the fields 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?

States a specific verb (Modifie), resource (galerie) and exactly which attributes are updatable (titre, thème, police du titre). It explicitly carves out what is out of scope (photos, logo, texte d'accueil), which distinguishes it from sibling set_gallery_logo and create_gallery.

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?

Provides concrete routing guidance: use list_galleries to obtain the slug identifier, and states the updates are optional/partial ('et/ou') and non-destructive to unrelated assets. Does not explicitly name a when-not alternative, but the exclusion list effectively steers toward the right siblings.

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