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

Annotations cover the safety profile (readOnly, idempotent, non-destructive), yet the description still adds high-value behavior: credentials come from linked accounts and never from an argument, ambiguous multi-account calls fail and list accounts, an expired login fails asking for reconnect, and results are scoped to the previous working day. This is information the annotations cannot convey.

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?

Front-loaded with the return shape, then usage, then credentials/failure behavior — a logical ordering with no filler sentences. The return-field enumeration is long but earns its place because there is no output schema defining those fields.

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?

With no output schema, the description fully compensates by enumerating the returned object and its buckets, and it covers the three-parameter surface, auth sourcing, and failure modes. An agent has everything needed to call it correctly and interpret the result.

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 100% so the baseline is 3, but the description goes beyond the schema by stating the argument-selection rule (no arg with one linked account; pass provider or host with several) and the failure mode on ambiguity. It does not add format details beyond what the schema enums already establish.

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 (collect standup data from linked GitLab/GitHub) and names the exact return shape (today, previousDays[], myMrs[] bucketed, reviews[], blockers[]). The scope 'merge-request-based' and 'snapshot, not a search API' cleanly separates it from siblings get_note_instructions and post_standup_note.

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 explicit when-to-use ('once at the start of a working day, to write a standup note') and explicit when-not ('cannot fetch one named merge request, reach further back than the previous working day, or filter by project'). The alternative tool for posting results is implicit but the boundaries of this tool are unambiguous.

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