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

Annotations already declare readOnly=true, openWorld=true, destructive=false, so the safety profile is covered. The description adds useful context beyond that: the returned field set and the auth prerequisite ('needs the user's Cotlet API key with access to this app'). It doesn't mention pagination despite page/per_page params.

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?

Front-loads the operation, then the return fields, then the usage rule and auth note. Every sentence contributes, though the sentences are dense run-ons rather than cleanly separated points.

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?

Covers purpose, search keys, returned fields, intended usage, and the auth requirement, which is enough for a read-only lookup with no output schema. Missing only pagination behavior, which the description never touches despite page/per_page params.

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%, so the schema already documents all four parameters including the query search scope. The description's 'find by name, VAT number or tax code' largely restates the query parameter's schema text, adding little beyond it. Baseline 3 is appropriate.

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 ('Find clients') plus the exact search keys (name, VAT number, tax code) and the fields returned. An agent can distinguish this lookup from fatture-in-cloud_create_client without opening either 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 explicit context: 'Use it to match a client before create_invoice and to avoid creating duplicates.' That is a clear when-to-use with the sibling create_invoice referenced. It stops short of stating when not to use it or naming a retrieval alternative.

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