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

Annotations already cover safety (readOnly, idempotent, non-destructive), so the description focuses on return-value behavior: plain-text description truncated at 2000 characters when description_truncated is true, plus citation rules ('Cite hub URLs on the card. No employer apply URL.'). It doesn't explain error behavior or what happens with a stale/invalid url, which keeps it from a 5.

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 trigger condition and input source; every sentence carries instruction. The trailing 'Cite hub URLs on the card' sentence is slightly cryptic out of context but still earns its place as output-usage guidance.

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?

No output schema exists, and the description steps in to describe the returned content (plain-text, truncation flag), attribution expectations, and what is deliberately absent (employer apply URL). For a two-parameter read tool that is enough to call it correctly.

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 parameter descriptions already state provenance and preference ('Prefer this'), so the description's 'Pass that job's url ... (or its slug)' largely restates the schema. Baseline 3 is appropriate.

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 action (fetch one job) and distinguishes it from the search siblings by name: 'Use after search_jobs or hiring_now when the user picked one job' plus 'Do not use this to search.' An agent can tell exactly what this tool is for 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 preconditions (after search_jobs or hiring_now, once a job is picked), the input source ('Pass that job's url from search_jobs or hiring_now (or its slug)'), and an explicit exclusion ('Do not use this to search'). This is when/when-not coverage with named alternatives.

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