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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real behavior the annotations don't: results start tomorrow, the horizon is day-count based, times are the company's local timezone, and each entry carries a slot_id consumable by book_appointment.

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?

Short and front-loaded, with the prerequisite and the downstream consumer stated early. The telegraphic fragments and stacked parentheticals (e.g. 'At the company chosen from find_companies (pass its `company`).') make it slightly harder to parse than needed but nothing is padded.

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 5-parameter read tool with a nested answers object and no output schema, the description covers all the non-obvious requirements: where inputs come from, that nested answers/units change slot duration, the timezone of returned times, the starting day, and the slot_id return field. Nothing essential to a correct call 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; the description earns above that by explaining the causal relationship the schema only hints at — answers and units determine how long the work takes, which is why they affect availability. It also reinforces the provenance of `company` and `service`.

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 the resource precisely (free start times for a service at a company) with scope qualifiers: from tomorrow, over the next N days, in the company's local time. It also distinguishes itself from siblings by naming find_companies as the input source and book_appointment as the consumer of the returned slot_id.

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?

The call chain is explicit: get `company` from find_companies, `service` from list_services, then pass the returned slot_id to book_appointment. That gives clear when-to-use context, though there are no explicit exclusions or failure-mode guidance (e.g. what to do when no slots exist).

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