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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so safety is covered. The description adds genuinely useful context beyond them: the data is measured over five runs each on Claude Code and Codex, tied to a dated benchmark snapshot, and returns typical and worst-case figures.

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 sentences, front-loaded with the resource and scope, followed by the usage instruction. Dense but every clause carries information; no filler or repetition.

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 full burden of describing return values, and it does: job identity, input size, and typical/worst-case tokens and dollar cost. The fixed count of ten jobs and dated snapshot remove ambiguity about volume and freshness.

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% and the single enum parameter is fully documented in the schema, so baseline is 3. The description mentions that measurements exist for both Claude Code and Codex, which loosely motivates the filter, but adds no new detail about the parameter's behavior or defaults.

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 ('Lists the ten everyday jobs in Agent Blueprint's measured agent cost benchmark'), plus the benchmark date and the exact contents of each entry. An agent can distinguish it from estimate_agent_cost and check_agent_one_page without opening the 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?

Gives explicit when-to-use guidance: find the benchmark job closest to a target task, before estimating that task's cost. This implicitly sequences it ahead of estimate_agent_cost, but no explicit exclusion or 'don't use for X' case is stated.

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