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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds useful context about the shape of the decoded output (cliff detection, backloaded patterns like 5/15/40/40, plain-English description), but says nothing about failure modes, unknown slugs, or rate/volume limits.

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?

Dense and front-loaded with the output contract first, then the input requirement and the array-shape caveat. It runs long in a single block and mixes return-value detail with invocation rules, but no sentence is pure filler.

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 one required parameter, no output schema, and no nested objects, the description compensates well by describing the returned vesting fields in detail so the agent needn't guess. It lacks coverage of edge cases (missing/unknown slugs, multiple companies returned in what container), which keeps it from full marks.

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 single parameter is typed as an array with an example, so the description's array-must-be-array reminder mostly restates the schema. The one genuine addition is that values are company slugs resolvable via search-companies, which gives the agent a source for valid values.

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?

Names a specific verb+resource ('Get equity vesting schedules') and enumerates exactly what is returned (per-year percent, frequency, cliff, back/front/linear loading, RSU vs options). It does not distinguish itself from the sibling search-companies-by-vesting, which sounds like an adjacent capability, so sibling differentiation is only partial.

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 a concrete prerequisite/workflow: 'Pass company slugs (use search-companies to resolve names first)', which is real routing guidance to another tool. It stops short of saying when to prefer this over search-companies-by-vesting or what to do when a slug yields no data.

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