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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so safety is covered. The description adds genuinely new context the annotations cannot carry: the tool works before account linking, and the result set changes with link status (accountLinked false plus local markets and cost indexes for linked accounts). It does not mention result size or ordering, but that is minor.

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?

Three sentences, front-loaded with purpose, then downstream use, then the account-linking nuance. The parenthetical in the last sentence is dense but every clause carries information; there is little waste.

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 zero-argument discovery tool with a full output schema, the description covers purpose, downstream consumer, and the one behavioral variable (account linking) an agent needs to interpret results correctly. Return-field details like 'code, name and state' are partly redundant with the output schema but harmless.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate. It still usefully frames what the (empty) input implies — all supported markets are returned unfiltered — which is the only parameter-adjacent guidance available here.

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 ('List the regional construction pricing markets supported by Portravo') and immediately ties the result to downstream use as accepted metro_code values for create_project, which no sibling does. An agent can distinguish this from create_project, list_projects, and get_profile without opening the schema.

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 makes usage implicit but clear: call this to obtain valid metro_code values before create_project, and it works prior to account linking. It does not state any explicit exclusions or name an alternative tool, so it stops short of a 5.

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