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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true), so the bar is lower, and the description still adds real value: history/timestamp recording, the no-op behavior when setting the same status, and explicit error semantics ('not_found' for missing/foreign id, 'invalid_payload' for unknown status or empty update). The only mild redundancy is stating return values when an output schema exists, which keeps this 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-loads the purpose, then layers in status vocabulary, side effects, return shape, and error codes in dense but non-redundant sentences. No filler; every clause carries information an agent needs to call correctly.

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?

For a mutation tool with annotations, nested input, and an output schema, this covers the remaining gaps: valid status domain, side effects on history, idempotent no-op, required-field constraint, and both failure modes. Nothing material for correct invocation is missing.

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?

Reported schema description coverage is 0%, so the description must compensate: it restates the valid status list, explains that vacancy_id identifies a tracked vacancy (foreign ids yield 'not_found'), and enforces the at-least-one-of-status/notes rule. It does not mention the notes replacement/clear semantics or the 5000-char limit documented in the schema, so the compensation is not complete.

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 ('Update the job-tracker status and/or notes of a tracked vacancy') and enumerates the exact status vocabulary (new | applied | interview | offer | rejected | accepted), which distinguishes it from siblings like update_resume_section or archive_vacancy. Concrete examples ('mark it applied...', 'rejected when they got a no') make the intent unambiguous.

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?

Provides clear triggering context via examples of when an agent should call it (user reports sending an application, or a rejection). It also states the precondition that at least one of status/notes is required. It does not name alternative tools for adjacent needs (e.g. archive_vacancy), so it stops short of explicit when-not guidance.

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