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

Annotations already declare readOnly, idempotent and non-destructive, so safety is covered. The description adds genuinely non-duplicative traits: it is free, requires no account, performs no model call and no website fetch — exactly the cost/side-effect information an agent needs before deciding to call it.

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, front-loaded with the action and the returned content, followed by the usage cue. No filler or restatement of the tool name.

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 usefully enumerates what is returned (targets, availability, limitations, connection details). That largely compensates for the missing return contract, though "connection details" stays vague about whether it includes endpoints, auth requirements or quotas.

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 and the schema has 100% description coverage, so the baseline is 4. The description adds nothing about parameters, but there is nothing to add for an argument-less tool.

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?

Specific verb ("Read") plus a concrete resource set: GEO targets, availability, limitations and connection details. An agent can tell it apart from siblings like geo_list_targets or geo_quote_observation, but the description never names which sibling it supersedes, so differentiation is inferred rather than stated.

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?

"Free; no account, model call or website fetch" and "Use before proposing a paid observation" give a clear precondition and sequencing cue relative to the paid observation siblings. No explicit when-not or named alternative is given, so it stops short of a full routing rule.

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