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

Adds substantial context beyond the annotations: the exact-match credential requirement, the deliberately opaque failure mode (found=false, never says which half was wrong), the explicit no-PII guarantee, and per-caller rate limiting. These are behavioral facts an agent could not obtain from readOnlyHint/idempotentHint.

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 purpose, then the matching rule, then reference formats, then return contents. Every sentence adds a distinct, load-bearing fact with no padding.

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 no output schema, the description fully describes the return payload (plain-word status, next steps, booked/paid/received/completed/shipped dates, tracking number and link) and the failure shape. Nothing needed to call or interpret this tool 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?

Schema coverage is 0%, so the description carries the full burden and does: it gives concrete reference formats (BK-1A2B3C4D from the booking email, 20260923-114935-a3582466 from the enquiry confirmation) and defines email as the address the repair was booked with. This is information absent from the bare string-typed schema.

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 resource (one Hark Tech repair booking or repair enquiry) and scope (progress, for the customer it belongs to). An agent can distinguish it from get_order_status and get_quote without opening any 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 operating conditions: both reference and email must match, 'ask for both and do not guess', and distinguishes the two reference formats and their sources. It does not name a sibling tool as an alternative, so it stops just short of full routing guidance.

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