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

Annotations already declare read-only, idempotent and closed-world, but the description adds genuinely new behavioral facts: the data is a daily snapshot (as_of), cells with fewer than 30 jobs are suppressed, and no account is needed. The suppression threshold and freshness window are exactly the kind of context an agent cannot get from annotations or schema.

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 payload (percentiles), then constraints, then the alternative tool — a sensible ordering. It is dense but nearly every clause earns its place; the parenthetical "(see as_of)" is slightly cryptic without a defined output field.

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 still conveys the return shape (percentiles, sample size, recommendation) plus the two things an agent must know before calling: the snapshot cadence and the small-sample suppression. Nothing material is missing for a zero-required-parameter read tool.

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 schema already explains role/title synonyms, place formats and seniority values. The description only adds the default-US behavior and that seniority is optional, which is marginal added meaning. Baseline 3 applies when the schema carries the parameter burden.

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 resource (posted pay percentiles 25/50/75/90) with concrete inputs (title, place, seniority) and even names the returned extras (sample size, short recommendation). This is clearly distinguishable from count_jobs and the other market_* siblings, which deal with counts and breakdowns rather than pay percentiles.

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?

Explicitly routes the agent away from this tool for live counts or current hiring activity ("use count_jobs"), which is a real when-not-to-use statement. It does not differentiate against the other siblings such as market_breakdown or market_lookup, so the routing guidance is partial rather than complete.

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