Find a Pi session

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds that only primary sessions are returned (nested subagent/artifact sessions excluded) and how to recover from a project-scoped miss, but says nothing about ordering, pagination behavior, or result shape beyond what the schema states.

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 tight sentences, no filler. The core capability is front-loaded and the scope-retry caveat follows immediately, so an agent can act after one read.

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 4-parameter, fully documented, read-only lookup tool with an output schema, the description supplies the essential purpose and the one non-obvious operational decision (when to widen scope). Nothing critical is missing, though it could note the exact-match requirement relative to the fuzzy search sibling.

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 limit, cursor, scope and session_id are all documented in the schema itself. The description only re-touches scope's retry semantics, adding no syntax or format detail beyond the structured fields.

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, resource and matching mechanism: find primary Pi sessions whose filename ends in the supplied complete UUID. The 'primary' qualifier and exact-UUID matching distinguish it from the broader sibling pi_session_search.

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 an explicit condition for widening the search: 'Retry with scope all only when the UUID may belong to another project.' That is clear when/when-not guidance for the scoping parameter, though it never names pi_session_search as the alternative when the UUID is unknown or partial.

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