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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, yet the description still adds real behavioral context: newest-first ordering, the set of qualifying events, and the semantics of `days_in_previous_stage` including when it is null. It stops short of describing page-size limits or total-count behavior, which the schema partly covers.

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-loads the core identity ('as a log of moves, newest first') and keeps the parenthetical on `days_in_previous_stage` tight and necessary. The second sentence earns its place by supplying use cases and the sibling routing, though the whole is on the denser end.

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 carries the return-value burden and does it well, describing the log entries, ordering, and the meaning of each field mentioned. Minor gaps remain around pagination/result-count behavior, but an agent has enough to call it correctly.

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 every parameter (to, from, page, company, per_page, to_stage) is already documented in the schema, including the enum note. The description adds no syntax or filtering detail beyond the schema, so the baseline 3 is appropriate.

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 (the user's deal pipeline activity) and enumerates exactly what counts as an event: entry, stage change, pass, promotion to portfolio. An agent can distinguish this from sibling list tools and get_company without opening a schema.

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?

Names the alternative explicitly — one deal's own history lives in get_company under pipeline_history — and frames the use cases as concrete questions ('what moved this week', 'what did I pass on last quarter'). Both the when-to-use and when-to-use-something-else conditions are stated.

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