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

Annotations are absent, so the description carries the burden. 'via Open-Meteo' is a useful behavioral disclosure, implying a live external network call with its usual failure modes, and read-only character is inferable from 'Current temperature'. However, return format, units, and error behavior for unknown cities are not disclosed.

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?

A single eight-word sentence that front-loads the resource, scope, and data source. Every word earns its place; there is no filler, restatement of the schema, or low-value preamble.

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?

Complexity is low and the core invocation is guessable from 'city', but the bloated shared schema, absent annotations, and absent output schema leave units and response shape unspecified. It is adequate for a low-stakes read tool yet carries clear gaps an agent must resolve by trial.

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 schema already documents every parameter including 'City name for a public weather hint; discarded after the call'. The description adds only the word 'city', marginally reinforcing which of the ten parameters matters, but it does not compensate for the nine irrelevant shared-schema parameters that could mislead an agent.

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 names a specific resource, current temperature for a city, and the data provider (Open-Meteo), which distinguishes it from siblings like geo-hint or lib-docs-hint by subject. It lacks an explicit verb ('get'/'fetch') and leaves the relationship to the 10-parameter schema implicit, so it stops short of a 5.

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?

No guidance on when to prefer weather-hint over nearby siblings such as geo-hint, utc-time, or web-fetch, and no exclusions or context like 'use for quick lookups, not forecasts'. The agent must infer usage entirely from the tool name and the bare description.

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