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

Annotations already declare readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: results are per-cottage, flag free stays and party fit, and explicitly exclude the cleaning fee and taxes. This is meaningful cost-semantics disclosure that annotations cannot carry.

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?

Two sentences, no filler. The output scope is front-loaded and the cost caveat/routing note is compressed into a single clause after the colon.

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 not be described. The description covers the two things an agent cannot get from structured fields: what the figures exclude and which sibling to use for a total. 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 description coverage is 100%, so the baseline is 3. The description earns above baseline by explaining that the guest count is used to evaluate 'whether it sleeps the party' — a semantic purpose the schema's 'How many people.' does not convey.

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?

The description states a specific resource and scope: 'Every cottage's price for a stay', plus two derived outputs (whether it is free, whether it sleeps the party). It also distinguishes itself from the sibling quote_trip by reserving the all-in total for that tool. An agent can tell exactly what this returns without opening a 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?

It names the alternative tool (quote_trip) and the condition that selects it ('the all-in total'), which is solid routing guidance. It stops short of an explicit when-to-use/when-not framing (e.g. comparing cottages vs. committing to a booking), so it is clear context rather than full guidance.

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