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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false and openWorldHint=false, so the mutation profile is covered. The description adds a genuinely useful behavioral fact not present in the structured data: the required 'project_cost_snapshots:write' scope. It stops short of saying what happens on a duplicate date or whether values are immutable once recorded.

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 short sentences with zero filler; the core purpose is front-loaded and the prerequisite scope follows. Every clause 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 6-parameter mutation with full schema coverage and complete annotations, plus an auth-scope note, the agent has nearly everything needed to invoke it. The remaining gap is edge-case behavior (duplicate snapshot for the same date, effect of the non-idempotent flag), which is minor.

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 all six parameters (project_id, snapshot_date, total_budget, actual_cost, forecasted_cost, percent_complete) are already documented with types and constraints. The description adds no parameter-level detail beyond what the schema provides, so the baseline of 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 ('Record a cost snapshot for a project') with a temporal qualifier ('at a point in time') that pins down the semantics. It is clearly distinguishable from get/list/delete_project_cost_snapshot, though it does not explicitly differentiate itself from the many other create_project_* siblings.

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?

No when-to-use guidance, no pruning of alternatives (e.g., create_project_update, create_project_budget_item), and no statement about when a snapshot should be recorded versus updated. The reader must infer the trigger condition entirely.

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