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

With no annotations, the description carries full burden, and it delivers: it discloses the CPM method, progress-aware duration, return fields, and detailed limitations (only FS dependencies, business days behavior, no holiday table, ignores segments, no resource calendars). It also documents the cyclic_dependency error case. This is comprehensive behavioral disclosure.

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?

The description is well-structured: purpose, method, return values, limitations, and error handling each get a sentence. No wasted words; every sentence adds essential information. Despite being longer than average, it earns its length through density of useful content.

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?

The tool has no output schema and no annotations, so the description must cover return values and edge cases. It does this thoroughly: lists returned fields, explains defaults and limitations, and describes the error response. For a computational tool with 3 params, this is fully complete.

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 the baseline is 3. The description mentions business_days behavior and as_of_date, but these duplicate the schema descriptions. It adds no new parameter-level semantics beyond what the schema already provides, so the baseline holds.

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 clearly states the tool calculates the critical path of a project and returns it as data. It uses a specific verb ('calculate') and resource ('critical path of a project'), and distinguishes itself from sibling CRUD/list tools by emphasizing it's an analysis tool that shouldn't be replaced by manual reasoning over task lists.

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 provides clear usage context: use this to get critical path data instead of reasoning over raw task lists. It does not explicitly name alternatives or state exclusions, but the purpose and limitations make when to use it obvious. The absence of an explicit 'when-not-to-use' prevents a 5.

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