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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds real value beyond that by disclosing what the response contains — allowance, used, remaining, in both days and hours, plus the period — which is genuinely useful given there is no output schema. It stops short of stating permission requirements or whether the figures are computed live.

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?

A single compact sentence that front-loads the resource and then enumerates the returned fields, with the endpoint path trailing as optional routing detail. No filler, though the raw 'GET /team_members/{id}/leave_allowance' string is of marginal value to an agent that already selects tools by name.

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 one-parameter read tool with full annotation coverage and no output schema, the description supplies the key missing piece: what the response measures. An agent can call this correctly with the given information; only the absence of any guidance about the related bulk/adjustment tools keeps it from being fully complete.

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 description coverage is 100% for the single team_member_id parameter, so the schema fully documents it. The description's phrase 'one team member' merely restates the parameter's cardinality without adding format, source, or lookup semantics beyond the schema's 'Charlie team member id.' Baseline 3 applies.

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?

Specific verb + resource: retrieves the 'current holiday allowance of one team member' and even enumerates the constituent figures (allowance, used, remaining, in days and hours). The singular scope implicitly distinguishes it from the plural sibling list_leave_allowances, though that sibling is never named.

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?

Usage is only implied: 'current' signals a point-in-time snapshot (no history) and 'one team member' signals a per-member lookup versus the bulk list_leave_allowances. There is no explicit when-to-use statement, no mention of alternatives such as list_allowance_adjustments for adjustment history, and no prerequisites.

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