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

The annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely non-structured context: title/summary/description are unverified employer source text, licence requirements and eligibility are unassessed, and posting carries first-seen/last-seen-live timing plus closesAtLocal with its weekday/time meaning. Missing only failure behavior for a bad or expired id.

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 the action and its payload, then the data-quality caveat, then the timing fields. The final sentence is slightly compressed — "posting gives its age" reads as a return-field note and takes a moment to parse — but nothing is redundant.

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 a single required parameter and no output schema, the description carries the return-value burden and does so reasonably: it lists the fields returned and explains the temporal fields. The main gap is the absence of any not-found or expired-posting behavior, which matters for a lookup 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 0%, so the only parameter is documented solely by its uuid format and pattern. The description's "by its id" confirms it identifies a single posting but adds no guidance on obtaining an id or handling a malformed one, leaving the schema to do nearly all the work.

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?

"Read one posting in full by its id" gives a specific verb and resource, and the enumerated payload (description, requirements, pay, location, apply link) makes it clear this is a single-record retrieval rather than a search. It distinguishes itself from search_jobs and list_company_jobs in practice, though it never names a sibling explicitly.

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?

Usage is only implied: an agent can infer this is the drill-down after a search result, since it takes a single id. There is no stated when-to-use versus find_similar_jobs or list_company_jobs, and no mention of what to do if the id is unknown or the posting is closed.

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