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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds real behavioral context beyond that: it discloses the auth requirement ('Needs the user's Cotlet API key with access to this app'), the sort order ('newest first'), and the on-hold flag in the results. It does not describe pagination or result-limit behavior, so not a 5.

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 resource, which is good, but it is redundant: 'newest first' appears twice and the return fields are listed twice ('total' in sentence one, then 'total, currency, number of expenses'). It could be shortened by roughly a third without losing 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 no output schema, the description usefully enumerates the returned fields (status, total, currency, expense count, on-hold), and the annotations carry the safety profile while the description carries the auth prerequisite. It is largely complete, missing only pagination/cursor behavior which the schema covers.

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 the schema already documents all six parameters including the status enum and defaults. The description merely restates the status values that the enum already provides and notes the sort order, adding little beyond the schema. 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 ('Lists') and resource (reports in a workspace) and previews the returned fields, which is enough to separate it from get_report/list_expenses. However it never names a sibling or scope boundary explicitly, and the opening sentence ('Reports with status, total, submitter and approver, newest first') partially restates the resource without adding the list verb, so it falls short of a 5.

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?

'Filter by status to find what waits for you' implies a usage scenario (locating reports awaiting approval), but there is no explicit when-to-use vs. when-not, and no routing against the obvious alternatives expensify_get_report or expensify_list_expenses. Usage is only implied.

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