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

Beyond the readOnly/idempotent annotations it discloses page size, the full per-workspace return fields, and a non-obvious data-freshness rule: free figures and project counts are each machine's latest sample, absent plus `incomplete` when a machine did not answer. It also names the two refusal errors, though the phrasing of those sentences is compressed and takes a second read.

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?

It is front-loaded and has no filler, but the prose is elliptical and run-on ('20 a page', 'read now: one that did not answer in time leaves them absent'), which slows parsing of otherwise high-value details. Information density is good; readability of individual clauses is not.

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-shape burden and does so: paging, exact fields, conditional holding_project, staleness semantics, and error outcomes. An agent has enough to call it correctly and interpret the response without further probing.

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 coverage is 100%, so both parameters are already documented, including the holding_project behavior of project_id. The description restates that behavior and adds only the pagination size ('20 a page') and the NoMachine/WorkspaceNotGranted refusal modes, which are output/error semantics rather than new parameter meaning.

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 names the resource and its scope precisely: 'The workspaces the caller may reach', and enumerates what comes back per workspace (id, name, size, free, location, hostname, apps domain). The listing verb is implied rather than stated, and sibling differentiation is only partial ('The one call that takes no `workspace`'), which keeps it just 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?

It gives an implicit condition for the optional parameter ('With project_id, also which of them hold a project of that id') and a negative scoping note that it is the only call without a `workspace` argument. It never says when to prefer this over GetProject or other enumeration tools, so usage is 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.