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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description contributes real value beyond that by disclosing result ordering ('newest first') and cross-tree scope, but it says nothing about how recency is tracked, per-user vs. per-workspace, or behavior when recents are empty.

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?

A single compact sentence with zero filler, front-loading what the tool returns and then the ordering and scope qualifiers. Nothing redundant is included.

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?

For a one-parameter, non-destructive read tool with full annotation coverage and no output schema, the description covers the essentials an agent needs. The only residual gaps are the absence of sibling routing and empty-result behavior, which are minor at this complexity level.

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?

There is a single optional parameter with 100% schema description coverage ('1 to 50. Default 20.'), so the schema carries all the semantics. The description adds no detail about limit behavior, which is acceptable at baseline 3 but is a missed opportunity to mention truncation of recents.

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?

The description identifies a specific resource (boards the user opened recently) and adds two differentiating qualifiers: recency ordering ('newest first') and scope ('wherever they sit in your board tree'), which separates it from list_boards and search_boards. It stops short of naming those siblings explicitly, and the verb is implied rather than stated, so it is clear but not maximally sharp.

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?

Usage is only implied: 'opened lately' suggests picking this over a full hierarchy listing when the user wants recent activity. No alternative tool is named and there is no explicit when-not guidance (e.g., use search_boards to find a board by name).

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