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

Annotations already declare readOnlyHint/openWorldHint/destructiveHint, but the description adds real behavioral value by disclosing the return shape: 'compact rows, counts_by_state over the whole filtered set' — clarifying that counts span the full filtered set, not just the page. It does not discuss pagination limits, but the schema covers those.

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?

Core verb and scope are front-loaded in the first clause, and the second sentence delivers the usage directive. Dense but efficient with no filler, though the semicolon-heavy first sentence packs several ideas together.

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 15-parameter read-only search with no output schema, the description covers the filterable axes, the project scoping, and the result shape (compact rows plus counts_by_state). Nothing critical is missing, though pagination/sort behavior is left entirely to the schema.

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%, so all 15 parameters are already documented (including the 'open' state shorthand and assigned_user_id=0 semantics). The description restates the filter dimensions but adds no format or syntax detail beyond the schema, so the 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?

States a specific verb (search) and resource (pieces of ONE project) plus the filterable dimensions (type, state, assignee, author, text). The 'ONE project' scoping and 'no account-wide search' framing help distinguish it from a broader listing, but no sibling tool is named explicitly.

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 clear use case: 'Use for filtered questions such as state, assignee, author or text.' This tells the agent when the tool is the right pick, though it never names the alternative (e.g., ListPiecesTool) or states an explicit exclusion.

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