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

readOnlyHint=true already covers the safety profile, so the description only needs to add context. It adds the downstream workflow use (series id for draft invoices) but says nothing about what a series record contains or how filtering behaves. Adequate but thin beyond annotations.

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?

Two short sentences, front-loaded with the resource and followed by the actionable usage note. Nothing is wasted.

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 simple read-only list tool with no output schema, the description covers purpose and workflow but leaves return shape and two parameter semantics unexplained. It is minimally sufficient rather than 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 coverage is only 60%: 'prefix' and 'applicable_to' have no schema descriptions. The description mentions '(prefixes)' but never explains whether prefix filtering is exact or partial, and never clarifies applicable_to, so it fails to compensate for the coverage gap.

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 ('List invoice numbering series (prefixes)') and parenthetically clarifies what a series is. It is clearly distinguishable from the other list_* siblings by resource, though it doesn't explicitly contrast them.

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 workflow context: 'Use a series id when you create a draft invoice,' which links this read to quipu_create_draft_invoice. It gives no exclusions or alternative-tool guidance, but the intended usage point is unambiguous.

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