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

Annotations already cover the safety profile (readOnlyHint true, destructiveHint false, openWorldHint false). The description adds genuinely useful context beyond that: results are ordered newest first, visibility is permission-dependent with a markup difference between owner and member views, and the free-text fields are user-typed (a useful signal about untrusted content). It stops short of detailing pagination or default/max result behavior for an unqualified call.

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?

Three dense sentences that front-load the resource and ordering before moving to access rules and data provenance. Nearly every clause carries information, though the list of returned fields is a little inventory-like and could be tightened.

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 compensates by enumerating the returned fields and the ordering, and it explains the permission-dependent view differences — the key thing an agent needs to interpret results. Minor gaps remain around pagination and default result size behavior.

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 from/to/limit/userId/unbilled/boardId are all already documented with formats and defaults. The description adds no filter syntax or override semantics beyond the schema, so the baseline 3 applies.

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 ('Lists the expenses logged on a project'), plus the scope (newest first) and the field set returned. It is clearly distinguishable from siblings like list_time_entries or list_unbilled_work.

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?

The description clarifies who sees what (project owner sees everyone's with markup; other members see only their own without markup), which implicitly tells an agent when this tool returns the right data for a given caller. However, it never names an alternative tool or an explicit when-not condition, so usage guidance remains inferred rather than stated.

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