session_summary

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

Discloses side effect: runs consolidate() and rebuilds FTS search index. Lacks details on auth or error handling, but adequately covers behavioral impact.

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?

Well-structured with clear sections for purpose, usage, side effect, args, returns. Slightly verbose but each sentence adds value; front-loaded.

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?

Covers purpose, side effect, parameters, and return keys. Differentiates from siblings. Could mention edge cases or failure modes, but sufficient for typical use.

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?

Adds meaning beyond schema: 'Project fingerprint to scope the summary. Empty string auto-detects from cwd (recommended).' Explains purpose and default behavior.

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?

Clearly states 'End-of-session snapshot' and 'one-call overview' for session log or memory append. Distinguishes from siblings like stats and suggest by noting the side effect.

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?

Explicitly says 'Call this at the end of an agent session' and provides alternative: 'If you want a pure read-only summary, use stats() + suggest() separately.'

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