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

Annotations already declare readOnlyHint=true, destructiveHint=false, and closed-world scope, so the safety profile is covered. The description adds only the note that detail mode returns 'live completion progress', which is mild extra context. No mention of ordering, pagination, or empty-result behavior for the list mode.

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?

Two sentences, no filler, and the distinguishing condition (milestone_id vs project_id) is front-loaded in the first clause. Every sentence earns its place.

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 two-parameter read-only tool with full schema coverage and safety annotations, the description covers the essentials an agent needs to choose a call path. It is slightly thin on list-mode behavior, but nothing critical is missing.

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% and both parameters already document ULID format, requiredness, and conditional behavior. The description restates the same either/or logic rather than adding new meaning, 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 (get milestone detail vs list milestones) and clearly separates the two modes by which parameter is supplied. It does not name or differentiate against any sibling tool, but the dual-mode wording is unambiguous about what comes back.

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 gives an explicit conditional: pass milestone_id for one milestone, otherwise pass project_id to list. That is clear routing logic for a single tool. It stops short of naming alternatives (e.g., tm_list_projects) or stating exclusions, so it does not reach 5.

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