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

Annotations already cover the safety/idempotency profile (readOnly=false, idempotent=true, destructive=false, openWorld=true), so the description's added value is the ambiguity-refusal behavior (returns candidates instead of guessing) and the reactivation/preservation semantics for an existing market. It stops short of stating auth requirements or rate limits, so a 4 rather than 5.

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?

It is front-loaded with the core action and uses short, scannable sentences for ambiguity behavior, the rank-check boundary, and the alternative routing. Slightly dense with the multi-tool 'Related' list, but every sentence carries useful information.

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 mutation tool with a full annotation set and an output schema, the description supplies the remaining decision-relevant context: ambiguity handling, reactivation behavior, parameter preservation, and explicit routing to alternative tools. Nothing an agent needs to call it correctly is missing.

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 schema already documents all four parameters and their defaults. The description reinforces the override-vs-keep behavior but adds no new syntax or format detail beyond what the schema states, so the baseline 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?

The opening sentence gives a specific verb and resource ('Creates or updates an active market') plus the input basis ('from a place name and language'). It also clarifies what happens under ambiguity, so an agent can distinguish it from siblings like save_strategy_item without opening schemas.

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?

It explicitly states when NOT to use it ('Does not start a rank check') and routes rename/deactivate/delete to save_strategy_item or delete_strategy_item with a named argument. It closes by listing related tools (list_market_locations, get_setup_status, get_brand_context, research_keywords), leaving little to inference.

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