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

With only readOnlyHint=true in annotations, the description carries the behavioral burden and does so well. It discloses ordering ('newest first'), the 'since we last looked' incremental semantics, the employer-only rule (title changes excluded), and the empty-result behavior on a watcher run ('on a run with nothing new it says so'). This goes well beyond the annotations and gives an agent accurate expectations.

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 description is longer than average but every sentence adds value: purpose, use cases, watcher role, employer-only rule, and exclusions. It is front-loaded with the core definition and uses the NOT structure to efficiently prevent misrouting. No fluff or redundancy.

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 must convey return semantics. It does: the list contains people, their old and new employers, newest first, and the empty case is explicitly described. Combined with the 100%-covered input schema and readOnlyHint annotation, an agent has everything needed to select and invoke the tool 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?

Input schema coverage is 100%, so the baseline is 3. The schema already documents days, limit, and refresh clearly, including defaults and a watcher-specific hint for days=1. The description adds no additional parameter-level meaning beyond what is already in the schema, so a 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?

The description opens with a specific, concrete statement: 'People in the user's network who have moved to a different company since we last looked, newest first, with where they were and where they are now.' This clearly identifies the verb (list/report), resource (network job changes), and scope. It also distinguishes itself from siblings by explicitly ruling out related concepts: NOT a list of who to contact, NOT the history with one person, NOT news about a company.

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?

The description provides explicit trigger phrases: 'Use when they ask who has changed jobs, who has moved recently, whether anything has changed at their contacts, or who is worth congratulating.' It also gives a special use case as a scheduled watcher and lists exclusions. However, it does not name specific alternative tools by name (e.g., company_signals for company news), so it falls short of the full 'alternatives' criterion.

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