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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), so the bar is lower, and the description still adds two real traits: the observation window is seven days, and the data is observed asking rents that do not guarantee current availability. It does not disclose result volume, the effect of 'limit', or whether cities with no cuts return an empty set.

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 short sentences, scope stated first and the data caveat second; every clause carries information and 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?

With no output schema, the description carries the burden of explaining what an observation record contains and how many come back, and it says nothing about return shape or the limit cap. It is adequate to know what the tool fetches and to trust the data appropriately, but thin for a tool with an undocumented parameter and no output contract.

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 only 50%: 'city' is well documented in the schema (slug format, resolved via list_covered_cities) but 'limit' has no description at all, only a 1-100 range. The description never mentions either parameter, so it does not compensate for the undocumented cap or clarify what limit actually bounds (records? properties? days?).

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 ('Read observed asking rent reductions') plus a precise scope: last seven days, one tracked city. An agent can distinguish it from get_rent_history and get_market_stats by the 'reductions in a city over 7 days' framing, though no sibling is named explicitly.

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?

Usage is only implied: the seven-day/single-city scoping tells the agent roughly when this fits, but there is no explicit when-to-use or when-to-prefer get_rent_history / get_market_stats guidance. The availability caveat is a data-qualification note, not routing guidance.

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