Table Mountain today

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

Annotations only declare readOnly/idempotent/openWorld, so the description carries the real burden and does so: it enumerates the returned fields (verdict, reasons, warnings, summit wind/gusts/cloud/rain/temperature, cable car status and hours), pins the timezone (UTC+2), and defines a data-freshness contract (check freshness.stale, follow freshness.note, don't present as current). It also disambiguates cableway.closedUntil as a reopen date rather than a last-closed date, which is exactly the kind of trap a naive reader would fall into.

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 the core question and the verdict payload, then usage, then scope, then caveats — a sensible ordering with no filler sentences. It runs slightly long and the freshness/cableway caveats are dense, but each clause encodes a distinct rule an agent would otherwise get wrong.

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 takes responsibility for describing the return payload, including conditional fields ('a better day this week if there is one'). Combined with the freshness and closedUntil semantics, an agent has everything needed to call it and interpret the result without further documentation.

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?

The tool takes zero parameters, so per the baseline this sits at 4; there is no parameter meaning left to add. The description does not waste words restating an empty schema, which is the right call.

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 opening sentence states a specific question-shaped verb ('Should someone go up Table Mountain TODAY?') plus the resource, verdict type, and the exact site the data comes from. It explicitly distinguishes itself from the sibling by naming find_best_day for other days, and scopes itself geographically ('Only covers Table Mountain').

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?

Gives explicit when-to-use ('questions about today or right now: going up, hiking, the cable car, wind or cloud on top'), explicit routing to the alternative ('For a specific day other than today, or "which day is best", use find_best_day'), and explicit exclusions ('Don't use it for other places'). All three routing decisions an agent needs are stated.

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