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

Annotations already declare a safe, idempotent read, and the description adds substantial behavior on top: the full text is not served, third-party content must be treated as data, missing fields (pay, overtime) are unknown rather than inferable, and pay/deadlines must be confirmed at the url. It also discloses failure modes the schema cannot express, naming removed_from_jobcontext for retired ids and not_a_posting for list pages.

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?

The core definition is front-loaded in the first clause and the return-shape detail follows logically, but the text is a dense single block that mixes data description, error semantics and lengthy scoring/ethics rules with no paragraph breaks. Every sentence is arguably load-bearing, yet the wall-of-text presentation makes it hard to scan.

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?

There is no output schema, so the description carries the full burden of describing returns, and it does so field by field (prefectures, location_scope, place_estimated, requirements, requirements_preferred, url, day, company name, hojin_bango, employees, type, site_url). It also explains the machine_extracted/not_extracted flags and the paired note fields, which is complete for a single-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 coverage is 100% and the id already has an example, so the baseline would be 3. The description earns above baseline by documenting the provenance of the id (the five sibling tools that emit one) and by specifying what happens when the id is out of service, which is meaning the schema cannot convey.

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 job posting by id" gives a specific verb and resource, and the description immediately lists the only valid producers of that id (search_jobs, filter_jobs, search_by_meaning, similar_jobs, get_company). That both scopes the tool and separates it from every sibling that returns lists or company data.

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?

It states explicitly when to use it and when not to: compare and shortlist with these facts, and open the url only when the user wants details or is about to apply. It also routes the agent to job_search_guide for notices and present items, which is a real alternative-use rule rather than an implied one.

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