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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered; the description adds genuinely useful semantics on top by defining issueCount as only visible issues (permission-scoped counting) and stating that an omitted workspaceId falls back to the credential's workspace. It does not say whether the whole label set is returned or truncated, which is the remaining behavioral gap.

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 sentences, each doing distinct work: what is returned, where to write instead, and how the single parameter resolves. The purpose is front-loaded and the parenthetical field definitions are compact rather than redundant.

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 correctly takes on the job of naming the returned fields and the visibility semantics of issueCount, and it resolves the optional-parameter default. It is nearly complete; only the question of result size/pagination or ordering is unaddressed for a list operation.

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 0%, so the description carries the full burden and does: workspaceId is optional, names the workspace to operate in, points to list_workspaces for enumeration, and specifies the credential default when absent. Nothing about the single parameter is left ambiguous.

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+resource ('Lista las labels del workspace') with the returned fields enumerated (id, nombre, color, issueCount), so the agent knows exactly what it gets. It explicitly separates itself from the write path ('Créalas o edítalas con save_label'), but never acknowledges the very similarly named sibling list_project_labels, leaving one obvious source of confusion unaddressed.

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?

Gives a clear when-to-use context (tagging issues) and routes mutations to save_label, plus explains how to discover workspaceId via list_workspaces and what happens if it is omitted. It stops short of an explicit when-not/alternative clause against list_project_labels or delete_label, so the agent must infer which label listing it needs.

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