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

Annotations already establish readOnlyHint=true and destructiveHint=false, but the description goes further: it discloses the return cardinality and fields (10 closest services with service_id, title, summary, score, starting prices and business-day delivery) and warns that score 'only ranks candidates; it is not a delivery guarantee.' The 'does not create an order' line partly restates the read-only annotation, 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?

Front-loaded with purpose, then usage, then parameter guidance, then return/caveat details. It is slightly long, and the 'does not create an order or change the catalog' clause overlaps already-declared annotations, but nearly every sentence carries distinct 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?

With no output schema, the description compensates by describing the result shape, count, fields, and price/delivery info, plus the interpretation caveat for score. Both parameters, the alternative tool, and the side-effect boundary are covered—nothing needed to call it correctly 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 coverage is 100%, so the baseline is 3, but the description adds real semantic value: the 'one per service the task needs' mapping, the instruction to pass the task in any language, and a concrete example query ('convert PDF bank statements to Excel'). That is more than a restatement of the schema's field descriptions.

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+resource+scope ('Finds predefined fixed-price services, delivered by people, for a customer's task'), which is unambiguous and clearly distinct from siblings like create-checkout-tool and get-service-tool. An agent knows exactly what this returns without opening the 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 trigger ('Use it when a customer describes a new task'), explicit re-call guidance ('can be called again with other phrases'), an explicit alternative ('Use get-service-tool to inspect scope and requirements before recommending a package'), and an explicit boundary ('does not create an order or change the catalog'). When-to-use, alternatives, and exclusions are all covered.

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