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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds genuinely new context: the tool is paid via x402, requires reading a pricing resource first, and returns bounded summaries rather than full records. It stops short of explaining what happens on an unpaid call or whether results are cached, which keeps it from a 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?

Four sentences, front-loaded with the payment caveat and the core verb, with the price ID and pricing-resource instruction earning their place. The return-value sentence is a dense field list, but each item is meaningful for an agent judging result trustworthiness.

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?

There is no output schema, so the description carries the return-value burden and does so by naming match reasons, confidence, provenance, public-use status, freshness, and quality scores. Combined with the payment prerequisite and the schema's cursor/limit documentation, an agent has enough to call this correctly; only error and rate-limit behavior are unaddressed.

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 query, limit, cursor, and entity_type are all documented in the schema itself. The description only restates the entity domains ('suppliers, locations, or organizations') and adds no syntax, matching behavior, or pagination detail beyond what the schema provides — 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?

States a specific verb and resource ('Search trusted public master data') and scopes the domains to suppliers, locations, or organizations, plus what the result contains. It does not name a sibling to contrast with, so an agent must infer that single-record retrieval belongs to get_master_data_golden_record and reference data to get_reference_data.

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 gives one concrete prerequisite ('Read masterdata://pricing before payment') and flags that this is a paid x402 tool, which is real usage guidance. It never says when to prefer this search over resolve_master_data_entity or get_master_data_golden_record, so the alternative-selection decision is left to inference.

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