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

Annotations already declare readOnly, idempotent and non-destructive behavior, so the safety profile is covered. The description adds real scope boundaries beyond that: it does not consult market prices, does not compute termination penalties, and treats pricing_type as a canonical input rather than an inferred value. It says nothing about permissions or failure modes, but for a read-only computation this is solid.

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 compact sentences, front-loaded with the core computation, followed by the exclusion and the routing instruction. No filler; each sentence carries a distinct constraint.

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?

An output schema exists so return values need no explanation, and the annotations carry the safety profile. Scope, exclusions and the sibling hand-off are all present; the only shortfall is that four of five parameters remain semantically unannotated.

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 0% across 5 parameters, so the description must compensate. It meaningfully clarifies pricing_type (a canonical value, never inferred from free text) and gestures at the inputs ('dates et clauses extraites'), but end_date, auto_renewal, evaluation_date and notice_period_days get no added semantics. Partial compensation for a full coverage gap.

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 precise verb+resource: it computes only the contract deadline and notice period from extracted dates and clauses. It immediately scopes itself against the sibling renewal_advisor, so an agent can distinguish the two 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?

Explicit when-to-use ('dates and clauses only, no market prices') and when-not-to-use ('for a renewal decision with market and catalog, call renewal_advisor'), plus an additional exclusion ('does not quantify termination penalty'). Both the alternative and the selecting condition are named.

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