Salesforce MCP Server

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

Annotations indicate readOnlyHint=false and openWorldHint=true, suggesting mutable and unpredictable behavior. The description adds context about error conditions and the custom nature of endpoints, but doesn't disclose critical behavioral traits like authentication needs, rate limits, or potential side effects beyond what annotations imply. No contradiction with annotations exists.

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 appropriately sized with two sentences that are front-loaded with the main purpose. It avoids unnecessary details, though it could be slightly more structured to separate usage notes from parameter explanations.

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 complexity of executing custom Apex endpoints, no output schema, and annotations covering only basic hints, the description is moderately complete. It explains the purpose and error case but lacks details on return values, authentication, or how to handle the open-world nature implied by annotations.

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 0%, so the description must compensate. It partially explains 'action' as 'the URL path after /services/apexrest/', but doesn't clarify 'method' (defaults to GET) or 'data' (payload for requests). With 3 parameters and low coverage, the description adds minimal semantic value beyond 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 clearly states the tool 'Call a custom Apex REST endpoint' with specific details about the URL structure ('path after /services/apexrest/') and that these are 'org-specific REST services written in Apex by developers.' It distinguishes from generic REST tools by specifying Apex endpoints, though it doesn't explicitly differentiate from sibling 'restful' or 'tooling_execute' tools.

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 implies usage for custom Apex REST endpoints and mentions an error condition if none exist, providing some context. However, it doesn't explicitly state when to use this tool versus alternatives like 'restful' or 'tooling_execute', nor does it provide clear exclusions or prerequisites beyond the error case.

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