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

The description discloses important runtime behaviors beyond the annotations: one-off invocation without adding the MCP, connect-link sharing for credentials, checkout/retry for paid tools, owner/admin requirements for writes, installed_in_toolkit vs installed_in_workspace flags, and the fact that writes include uninstall/uninstall/cancel plus the one-off install behind invoke. This is far beyond what annotations say.

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?

The description is long, but the tool itself is a sprawling 23-parameter multi-capability hub, so length is generally justified. It is front-loaded with the core marketplace purpose, followed by search→describe→invoke, then install, billing, prompts, and permissions. It could be tightened, but each sentence adds behavioral or workflow knowledge.

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?

Given the tool's complexity and the lack of an output schema, the description is unusually thorough: it covers discovery, execution, authentication, payment, permissions, installed flags, and the prompt library. However, it is not fully complete because the schema absent 'invoke' and several prompt/tool parameters remain unexplained, so the agent cannot confidently compose a well-formed request just from this description.

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?

With 23 parameters and 0% schema description coverage, the description must compensate, but it does not give a parameter-by-parameter mapping. It names action-search and several action values, but not the meaning of params, query, limit, prompt_access, tier_slug, report_context, conversation, etc. More importantly, it repeatedly says 'invoke runs that tool' but the action enum in the schema does not include 'invoke', leaving the agent an unresolved mapping between the described flow and the schema.

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 description explicitly identifies the tool as the mcp.ai marketplace, combining MCP discovery, execution, installation, billing, and prompt-library access. It clearly names the core actions (search, describe, invoke, install, subscribe/cancel, prompt actions) and differentiates the tool from focused siblings like report_bug or sefaz_df_ipva_consultar.

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 a concrete workflow: search by intent, then describe to pick the right tool_id, then invoke to run it. It also explicitly states when to use install instead of invoke, when to use list_tools, report_bug, request_mcp, and how to handle credential/checkout cases. This is excellent alternative-based usage guidance.

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