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

With no annotations, the description carries the full burden, but it does disclose two genuinely useful behavioral facts absent from structured data: a bearer key is required and the call returns a record id. It still omits write-side traits an agent needs, such as whether it is idempotent, what happens on duplicate student_name, or whether it replaces an existing ledger.

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?

A single front-loaded sentence with the action first, the return value parenthesized, and the auth requirement last. 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?

A 4-parameter mutation tool with no annotations, no output schema, and 25% schema coverage gets a one-line description. The agent cannot tell what the period parameters do or what the created ledger contains, which is too thin for this complexity.

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 only 25%, so the description must compensate and largely does not. It alludes to student_name ('one student') but says nothing about what period_start/period_end bound or how program is used, and period_end/period_start have no schema descriptions either.

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 concrete verb+resource: 'Open an hour ledger for one student', plus the return value (a record id). This distinguishes it from read-only siblings like check_hours or get_record_summary, though it never names an alternative explicitly.

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 and no comparison to siblings such as add_entries (which presumably populates the ledger this opens). The implied usage is only that a ledger gets created, leaving the agent to infer ordering and prerequisites.

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