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

Annotations already declare readOnly/openWorld/non-destructive, so the safety profile is covered. The description adds real value by disclosing the return fields (caller, called, duration, contact match, voicemail URL, unread flag) even though no output schema exists, and by stating the today-by-default window. Pagination behavior is left to the schema rather than the description.

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 dense sentences with the scope and default front-loaded, followed by return payload then the date override. The trailing "GET /calls" is minor implementation detail rather than agent-relevant information.

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 seven optional params, no output schema, and full schema coverage, the description covers what is needed: scope, default window, filter vocabulary, and the shape of results. Missing only explicit paging/volume expectations, which the schema already hints at.

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 all seven parameters are documented in structured form; baseline is 3. The description adds only a light restatement of the date default and the outcome filter vocabulary, without new syntax or format semantics beyond the schema.

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?

Specific verb (list) plus resource (incoming calls) plus scope (one day, today by default) and an enumeration of the outcome states covered. It is clearly distinguishable from placetel_get_call or placetel_list_call_center_calls by implication, but no sibling is named explicitly.

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?

"For a different day pass date" gives one concrete usage cue and the default-day behavior is stated, so day-based selection is clear. However, there is no guidance on when to prefer placetel_get_call (single call) or placetel_list_call_detail_records (history/CDR), and no exclusions or prerequisites.

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