One AI provider's latency in every region

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered structurally. The description adds meaningful behavior beyond them: the 24-hour data window, the enumerated probe regions, the exact metric set, and the error contract for an unknown provider id. Return format is not detailed, but an output schema exists to carry that.

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?

Three sentences, front-loaded with what the tool returns, then examples, then the alternative tool. No filler, no restatement of the title, and each sentence carries distinct routing or scoping information.

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 needn't be explained, yet the description still names the metrics and regions the agent will see. Combined with usage examples, the sibling routing rule, and the error behavior, everything needed to select and call this single-parameter tool correctly is present.

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 coverage is 100% and the format is already pinned by the schema (lowercase-with-hyphens, example ids), so the baseline is 3. The description adds a semantic the schema does not: an unknown provider id errors and lists the valid ids, which tells the agent how to recover from a bad value.

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+resource: 'Show how a single AI API provider performs from every probe region', with the exact metrics returned (rank, median and p95 TTFB, uptime, sample count) and the time window (24 hours). It explicitly contrasts scope with the sibling get_ai_api_latency, which is the full leaderboard, so an agent can distinguish them without opening either 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?

Provides concrete example questions ('is the Anthropic API slower from Asia than from Europe', 'was OpenAI reachable today') that map intent to this tool, and names the alternative get_ai_api_latency plus the condition that selects it (full region leaderboard). When-to-use and when-not-to-use are both covered.

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