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

'READ-ONLY. Returns data, changes nothing' merely restates the readOnlyHint/destructiveHint annotations already supplied, earning no credit. The only additive content is the cross-reference to po_documents_update_index for indexing fields, which is navigation rather than disclosure of this tool's behavior (e.g., match semantics, result 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?

Three short sentences, front-loaded with the read-only guarantee, with no filler. The final sentence about indexing fields is somewhat tangential to searching and could be mistaken for a parameter hint, but overall the structure is tight.

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?

An output schema exists, so return values need not be explained. The description covers safety posture, when to search, and a follow-on tool reference; the remaining gap is how to interpret or narrow a returned inner tool_id, which is minor for a single-parameter lookup.

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% and the single `query` parameter is fully documented in the schema as a natural-language query for an inner tool_id. The description adds no further syntactic or semantic detail beyond that, so the baseline of 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?

The verb+resource pair is specific: 'Search the tool catalog' tells the agent this searches MCP tool definitions, not documents (po_documents_search) or tags. The name po_mcp_tools_search plus the description make it distinguishable from all siblings, though it never explicitly contrasts itself with po_mcp_tools_schema or po_mcp_tools_call_read.

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?

'Search the tool catalog before saying an action is unavailable' gives a clear trigger condition for calling this tool, which is unusually actionable. It also points to po_mcp_tools_call_write / po_documents_update_index for the follow-on indexing operation, though it does not state when to prefer this search over po_mcp_tools_schema.

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