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

Annotations already declare the non-read/non-destructive profile, so the bar is lower. The description adds genuinely useful context: idempotency behavior ('Idempotent by name or idempotency_key'), a cost signal ($0.10), and an auth requirement (API key required) — all beyond structured fields.

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 compact sentences with the primary purpose front-loaded, then behavioral constraints. Efficient; slight density of parenthetical signals but no wasted sentences.

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?

Output schema exists so return values need not be explained, and annotations cover the safety profile. However, for a 21-param creation tool with 29% schema coverage, the description omits many parameter semantics and gives no explicit relationship to siblings like update_place or resolve_place.

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 29%, and the description only names a handful of fields (address, opening_hours, affordability, notes, tags) out of 21 params. It doesn't clarify the alias relationships (hours↔opening_hours, price_level↔affordability) that the schema does document, leaving substantial gaps the description does not compensate for.

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+resource ('Save a venue card') and enumerates the fields it holds (address, opening_hours, affordability, notes, tags). It is clearly a creation tool distinct from get_place/get_places/update_place siblings, but it does not explicitly name those siblings the way a 5 would.

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 clause 'does not create calendar notes' implies when-not usage by exclusion, but there is no explicit guidance on when to use create_place versus resolve_place or enrich_place_from_google. Usage is only implied.

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